Scare Glow is an Evil Warrior, who has the ability to burst forth and freeze enemies with fright, from his eerie glowing body. He is a skeletal ghost warrior, who seems to have a solid but translucent body, and whose bones emit a strong glow which can intimidate even the bravest opponents. He wears a long purple cape and carries a 'Scythe of Doom'.

Origin #1 (Mini-Comics & Marvel/Star Comics):

In the mini-comic "The Search For Keldor", Scare Glow is summoned to Eternia by Skeletor using a magic spell to call forth the most evil beings of space and time, although it is never stated which time period or dimension Scare Glow originates from. He is sent out with Ninjor on a mission to attack the Heroic Warriors with the power of his glow. He uses the glow to overpower Prince Adam, evoking in him so much fear that he is even too scared to change into He-Man. However, he is ousted from Adam's path by Clamp Champ, giving Adam the time to change into He-Man and subsequently defeat him.

Origin #2 (MOTU UK Magazines)

Another story that majorly features him is "Enter the Ninjor" in issue #11 of the UK Adventure Magazine, which gives him an origin as a being of pure light energy, created by Skeletor in his own image. Invisible in the light, but not in the dark, he is sent out with Ninjor to mount a series of silent, unseen attacks on He-Man and Fisto as they explore Viper Tower.

Origin #3 (MVCreations):

Scare Glow's was brought to Eternia by magic Elixir Of Schneidor used by Skeletor to bring Scare Glow to Eternia. Scare Glow reluctantly agreed to join forces with Skeletor, in hope that he will allow him to return to his own dimension. His first mission is to attack Teela and Man-At-Arms, while they and Adam are out testing the new Attack-Trakk. Adam gets away, and changes into He-man in order to combat the extra-dimensional spectre, but finds himself resoundly incapacitated by Scare Glow's fear hallucinations. Only a timely intervention by Orko saves the trio of heroic Warriors from destruction, and Scare Glow is defeated and sent packing back to a seriously displeased Skeletor. Skeletor tells him that, he won't return Scare Glow to his own dimension, unless he proves himself usefull to Skeletor's cause.

Origin #4 (MOTUC Bios):

In life, Nul was a shifty bounty hunter who spent years attempting to break into Castle Grayskull, obsessed with legends that within lay the power to become Master of the Universe. In death, he was cursed and banished into the dimension of Infinita - forever chained to his past crimes

Trivia (Clawful94): Scare Glow was released towards the end of the toy line, which explains why he was never in the Filmation animated series.